Oestrogen receptor expression and the effects of oestrogen and tamoxifen on the growth of human ovarian carcinoma cell lines

Abstract

To assess the role of oestrogen regulation in the growth of ovarian cancer, we examined the effects of an oestrogen, 17 β-oestradiol, and an anti-oestrogen, tamoxifen, on oestrogen receptor (ER) -positive and -negative human ovarian carcinoma cell lines. As measured by a dextran-coated charcoal adsorption assay, cell lines PEOl, PEO4 and PE06 possessed moderate concentrations of ER (96-132 fmol mg−1 protein), PEA1 and PEA2 had low values (12—23 fmol mg−1 protein) and PE014, TOM, PE023 and PE016 were ER- negative. Addition of 17 β-oestradiol (10 nM or 0.1 nM) to the ER + ve cell line, PE04, increased the growth rate. This oestrogen stimulation could be blocked by 1 μM tamoxifen. In contrast, the growth rate of the ER —ve cell line PEOl4 was unaffected by the addition of 17 β-oestradiol or tamoxifen. Concentrations of tamoxifen in excess of 8 μm were required to produce complete cytostasis in all lines. This concentration of tamoxifen over 72 hours also inhibited 50% colony formation when cells were plated on plastic. These data indicate that some ovarian carcinoma cell lines contain ER and their growth can be sensitive to oestrogen and anti-oestrogen modulation. © The MacMillan Press Ltd., 1990.